1. The Field of the Invention
The present invention relates generally to the field of optoelectronic devices, and more particularly, to systems, devices and methods for temperature cycle testing of optoelectronic transceiver modules.
2. Related Technology
Optoelectronic transceiver modules are commonly employed in fiber optic data transmission networks in the transmission and receipt of binary data signals. Among other things, an optoelectronic transceiver includes an optical transmitter, such as a laser, that receives electrical data signals, translates the electrical data signals to optical data signals, and then transmits the optical data signals. Further, the optoelectronic transceiver also includes an optical receiver, such as a photodiode, that receives optical data signals, translates the optical data signals to electrical data signals, and then transmits the electrical data signals. Optoelectronic transceivers can also include a printed circuit board (PCB) containing various control circuitry for the optical transmitter and/or optical receiver.
When manufacturing optoelectronic transceiver modules, each transceiver is tested to ensure that it functions properly. Since optoelectronic transceivers operate in environments characterized by any number of varying conditions, such as temperature and supply voltage for example, the transceivers are typically tested under conditions similar to those likely to be experienced in the intended operating environment.
However, for a number of reasons, testing optoelectronic transceiver modules has proven to be a costly activity. One reason for this is that optoelectronic transceivers are not readily disassembled or repaired once their components have been assembled. In this regard, it is generally the case that an optoelectronic transceiver will malfunction if there is a defect in the electrical component, such as the PCB, either of the optical components, or the connections between components. Thus, correction of the problem or defect often requires disassembly of the transceiver which, as noted above, can be difficult and, accordingly, rather costly.
Additionally, one of the aspects of the optoelectronic module that can be tested is the ability of the module to function over a wide temperature range. Typically, this has been accomplished by attaching the module to a testing board and placing the entire test board and module combination into an oven for testing over a range of temperatures. This approach to testing has proved problematic. For example, the printed circuit boards used as the testing boards are not designed to operate in the same temperature range as the optoelectronic modules. Therefore, when these boards are heated, they frequently fail, resulting in increased time and expense to conduct the tests on the modules, as well as time and expense to repair any damage to the test boards. Also, precise control of the module temperature is difficult to achieve in the oven due to variables such as the presence of air currents within the oven.
One approach to such problems has been to test the optoelectronic module components individually, and then assemble the module. While such an approach may help to eliminate the problem of determining which particular component is malfunctioning when the module is tested as a whole, such an approach may not provide useful information concerning the performance of the assembled module. Rather, the module must still be tested after final assembly to ensure that all connections are working properly. Thus, typical testing evolutions have involved a time consuming, and expensive, two step testing process where the module was tested firstly in the oven at one temperature and then secondly in the oven at a second temperature.